Hygienic hollow frame assembly

ABSTRACT

A cleanable frame and a method for making a cleanable frame having a simplified frame design. A hygienic conveyor frame assembly comprises a plurality of hollow tubular sections joined together to form an evacuated, sealed conveyor frame support structure that functions as a sterilization zone. An integral carryway is placed on the support structure. Lifters coupled to the conveyor frame can lift the canyway and conveyor belt for cleaning. Infeed and outfeed assemblies are also movable between operating and cleaning positions. A sensor can monitor the conditions of the frame interior to ensure that the vacuum is maintained and initiate a corrective action if the vacuum seal is breached.

BACKGROUND

The invention relates generally to frames formed of sealed hollow tubes.An application of the invention is frames for power-driven conveyors andmore particularly to belt conveyor frames that are easy to clean andmonitor for pathogens.

In food processing industries, such as meat, poultry, fruit, vegetable,dairy, and snacks, conveyor belts are used to transport food products.Most conveyor belts are supported along carryways and returnways thatare, in turn, supported by a conveyor frame structure. To meet USDAsanitation requirements, conveyor belt systems, comprised of the belt,frame structure and related conveyor components, must be cleanable.

In order to make the conveyor belt system cleanable, care must be takento eliminate potential bacteria harborage zones. It is well known infood industries that potential bacteria harborage zones include hollowareas that are not hermetically sealed, non-sealed interfacingcomponents (known as sandwiches), and threads. For this reason, therehas been a strong movement toward designs that eliminate threadedcomponents, sandwiches, and especially all hollow components. Hollowcomponents are undesirable because it has not been possible to verifythat hollow components remain hermetically sealed after installation.Further, sandwiches are often caused when there is a need to utilizedifferent materials, for example, stainless steel and UHMWPE, that arenot readily able to be sealed at their interfacing locations. As aresult, the materials are often sandwiched together, providing aharborage zone for bacteria.

Many conveyors are constructed of laser cut and formed stainless steelsheet metal. To obtain an adequate stiffness, many bends and welds arerequired, thereby increasing the surface area requiring to be cleanedand the angle from which cleaning can occur. The cost of building andcleaning such conveyor frame structures is high. Likewise, the conveyorframe structure is not as stiff as when made from stainless steel hollowtubing, which can increase vibration and noise.

Thus, there is a need to establish assurance that a hollow component isnot a potential harborage zone and to establish conveyor designs thatoptimize the interface where dissimilar materials mate for optimizedfunction and ease of cleaning.

SUMMARY

This need and other needs are addressed by a conveyor system embodyingfeatures of the invention. A hygienic conveyor frame assembly comprisesa plurality of hollow tubular sections joined together to form anevacuated, sealed conveyor frame support structure. An integral carrywayis placed on the support structure. Lifters coupled to the conveyorframe can lift both the carryway and conveyor belt for cleaning. Infeedand outfeed assemblies are also movable between operating and cleaningpositions. A sensor can monitor the internal conditions of each hollowsection or component to ensure that the vacuum is maintained andinitiate a corrective action if the vacuum seal is breached. Further,the sensor can monitor the internal conditions of each hollow componentto ensure that the conditions are not suitable living conditions forbacteria.

According to one aspect, a conveyor frame comprises a plurality ofhollow sections connected together to form a support structure for acarryway, the support structure extending longitudinally from an infeedend to an outfeed end and a sensor connected to one of said hollowsection for sensing a condition within the interior of the hollowsections.

According to another aspect, a method of monitoring a hollow conveyorframe comprises drawing a vacuum in the interior of the hollow conveyorframe and sensing a change in pressure in the interior using a sensor incommunication with the interior.

According to another aspect, a hollow conveyor frame structure thatsupports a conveyor belt circuit comprises at least one hollow framemember, wherein the interior of the hollow frame member is evacuated andsealed to have a pressure that is lower than the pressure of the ambientenvironment so that the pressure differential is negative, and a sensorin communication with the sealed region for measuring the pressure ofthe sealed region.

According to another aspect, a carryway for supporting a conveyor belttraveling from an infeed end to an outfeed end of a conveyor comprises aplurality of longitudinal plastic rails extending in the direction ofbelt travel, and at least one plastic cross member connecting at leasttwo longitudinal plastic rails to form a homogenous structure.

According to another aspect, a carryway lifter for selectively raise acarryway of a conveyor above support structure of the conveyor forcleaning comprises a lateral rail, a handle extending from a first endof the latera rail, a latching arm extending up from a middle portion ofthe lateral rail and offset from the handle, the latching arm forming anopen seat for a carryway rail, and a lifting arm in the middle portionfor lifting a carryway rail.

According to another aspect, a scraper assembly for a conveyor beltcomprises a pair of opposing mounting plates. Each mounting plate has aprotrusion for mounting a scraper assembly and a latch for receiving andlocking a leaf spring. A scraper assembly is mounted between themounting plates and comprises a pair of opposing arms that are pivotallymounted to the protrusions to form a first pivot point, a scrapermounting bar extending between the pair of opposing arms, a scraperblade mounted to the scraper mounting bar and a leaf spring connected tothe mounting bar, the leaf spring received in a latch to bias thescraper blade into contact with a conveyor belt.

According to another aspect, a drive head for a positively drivenconveyor belt comprises a pair of opposing mounting plates, a drivesprocket mounted between the mounting plates and a positionlimiter—scraper assembly. The position—limiter scraper assemblycomprises a roller extending between two connecting plates mounted tothe mounting plates and a scraper assembly having a scraper blademounted to the two connecting plates.

Accordng to another aspect, a roller for a conveyor comprises a shaftextending from a first end to a second end and a plastic element thatcompletely encapsulates the shaft and forms contoured enlarged portionsfor contacting a conveyor belt and troughed portions for minimizingcontact with a conveyor belt.

According to another aspect, a conveyor comprises a frame, a carrywayextending from an infeed to an outfeed and supported by the frame and acarryway lifter mounted to the frame for selectively raising thecarryway above the frame.

According to another aspect, a frame, comprises a plurality of hollowtubular sections connected together to form a support structure havingan evacuated and sealed interior and a sensor in communication with theevacuated and sealed interior for measuring the pressure of theinterior.

BRIEF DESCRIPTION OF THE DRAWINGS

These aspects and features of the invention are described in more detailin the following description, appended claims, and accompanyingdrawings, in which:

FIG. 1 is an isometric side view of a hygienic conveyor frame accordingto an embodiment of the invention;

FIG. 2 is an isometric top-side view of the hygienic conveyor frame ofFIG. 1;

FIG. 3 is an exploded view of the hygienic conveyor frame of FIG. 1;

FIG. 4 is a side view of view of the hygienic conveyor frame of FIG. 1with a conveyor belt trained around the infeed and outfeed end, with theconveyor belt and carryway lifted in a cleaning mode;

FIG. 5 shows the hygienic conveyor frame of FIG. 1 with the carrywaylifted in a cleaning mode;

FIG. 6 is an isometric view of a homogenous carryway according to anembodiment of the invention;

FIG. 7 is a bottom view of the homogenous carryway of FIG. 6;

FIG. 8 is a detailed view of the pins on the bottom of the carryway ofFIG. 7;

FIG. 9 is an isometric side view of an outfeed carryway and belt lifteraccording to an embodiment of the invention

FIG. 10 is an isometric front view of an outfeed carryway and beltlifter according to an embodiment of the invention;

FIG. 11 is an isometric rear view of an outfeed carryway and belt lifteraccording to an embodiment of the invention

FIG. 12 is an isometric side view of an infeed carryway lifter accordingto an embodiment of the invention;

FIG. 13 is an isometric front view of an infeed carryway lifteraccording to an embodiment of the invention;

FIG. 14 is an isometric rear view of an infeed carryway lifter accordingto an embodiment of the invention;

FIG. 15 is a detailed, close-up view showing an outfeed lifter in alowered, operating position;

FIG. 16A is a detailed, close up view showing the infeed lifter of FIGS.12-14 in a raised, cleaning position;

FIG. 16B is a detailed, close up view showing the outfeed lifter ofFIGS. 9-11 in a raised, cleaning position;

FIG. 17 is a cross-sectional side view of the conveyor frame andcarryway of FIG. 1 in an operating position, with the lifters lowered;

FIG. 18 is a detailed view of an infeed portion of the embodkment ofFIG. 17;

FIG. 19 is a detailed view of a middle region of the embodkment of FIG.17;

FIG. 20 is a detailed view of an outfeed portion of the embodkment ofFIG. 17;

FIG. 21 is a cross-sectional side view of the conveyor frame andcarryway of FIG. 1 in an cleaning position, with the lifters raised;

FIG. 22 is a detailed view of an infeed portion of the embodkment ofFIG. 21;

FIG. 23 is a detailed view of a middle region of the embodkment of FIG.21;

FIG. 24 is a detailed view of an outfeed portion of the embodkment ofFIG. 210;

FIG. 25 is an exploded view of the conveyor frame of FIG. 1;

FIG. 26 is another view of the conveyor frame of FIG. 1;

FIG. 27 is a detailed view of the outfeed portion of the conveyor frameof FIG. 26;

FIG. 28 is an isometric view of a position limiter—scraper assembly fora conveyor frame according to an embodiment of the invention;

FIG. 29 is an exploded view of the position limiter—scraper assembly ofFIG. 28;

FIG. 30 is an isometric view of the position limiter—scraper assembly ofFIG. 27 after unlatching it from an operating position;

FIG. 31 is an isometric view of the position—limiter scraper assembly ofFIG. 30 during a transition from the operating position to a cleaningposition;

FIG. 32 is an isometric view of the position—limiter scraper assembly ofFIG. 30 in a cleaning position;

FIG. 33 shows the removal of the position limiter—scraper assembly ofFIG. 27 from the conveyor frame;

FIG. 34 is an isometric view of a contoured infeed roller of anembodiment of the invention;

FIG. 35 is a front view of the contoured infeed roller of FIG. 34;

FIG. 36 is an isometric view of infeed roller mounting plates formounting the roller of FIG. 34 to a conveyor frame;

FIG. 37 is a detailed view of an infeed portion of a conveyor when thecontoured infeed roller of FIG. 34 is in a raised position;

FIG. 38 is a front view of a conveyor frame including the contouredinfeed roller of FIG. 34;

FIG. 39 is a cross-sectional view of the contoured infeed roller of FIG.38;

FIG. 40 is a bottom isometric view of a conveyor frame includingcontoured returnway roller according to an embodiment of the invention;

FIG. 41 shows a sensor in a conveyor frame used to monitor a hollowinterior of the conveyor frame according to another embodiment of theinvention;

FIG. 42 is a side view of a sensor suitable for monitoring a hollowinterior of a conveyor frame according to an embodiment of theinvention;

FIG. 43 is a top view of the sensor of FIG. 42;

FIG. 44 is a cross-sectional view of the sensor of FIG. 43;

FIG. 45 is an isometric view of the sensor of FIG. 42;

FIG. 46 is a front view of a vacuum tool and sensor during the processof inserting the sensor into cand show the process of inserting a sensorinto a port for a hollow according to an embodiment of the invention;

FIG. 47 is a front view of the vacuum tool and sensor of FIG. 46 duringevacuation of the hollow

FIG. 48 is a front view of the vacuum tool and sensor of FIG. 46 whilethe vacuum tool seals the hollow with the sensor;

FIG. 49 is a front view of the vacuum tool and sensor of FIG. 46 afterreleasing the vacuum tool, leaving the sensor to monitor the hollowaccording to an embodiment of the invention;

FIG. 50 is an isometric view of a sensor suitable for monitoring ahollow interior of a conveyor frame according to another embodiment ofthe invention;

FIG. 51 is another view of the sensor of FIG. 50;

FIG. 52 is a top view of the sensor of FIG. 50;

FIG. 53 is a side view of the sensor of FIG. 50;

FIG. 54 is a cross-sectional view of the sensor of FIG. 50;

FIG. 55 is a bottom view of the sensor of FIG. 50;

FIG. 56 is a top view of a sensor suitable for monitoring a hollowinterior of a conveyor frame according to another embodiment of theinvention;

FIG. 57 is a side view of the sensor of FIG. 56;

FIG. 58 is a cross-sectional view of the sensor of FIG. 56;

FIG. 59 is an isometric view of the sensor of FIG. 56;

FIG. 60 is another view of the sensor of FIG. 56;

FIG. 61 is a top view of a sensor suitable for monitoring a hollowinterior of a conveyor frame according to another embodiment of theinvention;

FIG. 62 is a cross-sectional view of the sensor of FIG. 61; and

FIG. 63 is an isometric view of the sensor of FIG. 61.

DETAILED DESCRIPTION

A conveyor frame embodying features of the invention is shown in FIGS.1-5. The exemplary conveyor frame 10 supports a conveyor belt 40 (shownin FIG. 4) traveling between a first end, the infeed 11, of the frameand a second end, outfeed 12, of the frame. The conveyor belt conveysproducts from the first end 11 to the second end 12 along a carryway.The conveyor belt 40 may be trained around reversing elements at eachend of the carryway and returned along a returnway 42 below thecarryway. The frame 10 minimizes components through simplification andintegration to enhance cleanability while ensuring sufficient strength.

The illustrative frame 10 comprises a plurality of hollow tubularsections forming support structure 20 for a carryway. A carryway 30 ismounted to the support structure for guiding the conveyor belt from theinfeed 11 to the outfeed 12. The infeed 11 comprises opposing mountingplates 110 configured to mount an infeed guide roller 114 and otherinfeed components if required. The outfeed 12 comprises opposingmounting plates 120 configured to mount a drive 124 for the conveyorbelt and other outfeed components. The frame also includes returnwayrollers 70 mounted to returnway mounts 72 below the carryway 30.

The illustrative support structure 20 comprises a plurality of round,hollow stainless-steel sections joined so as to provide support for thecarryway 30. The round rails are strong, yet lightweight and lessexpensive than solid stainless steel. The hollow interior of the supportstructure 20 is evacuated to inhibit growth of any living organismswithin the interior, to kill most living organisms within the interior,and sealed to prevent contamination. A sensor 210 may be provided tomonitor the seal and provide an alarm or initiate other correctiveaction if the seal is broken.

While the invention is not so limited, the support structure 20comprises an upper longitudinal rail 21 spanning the length of thecarryway, a lower longitudinal spine 22, transverse support rails 23 atthe infeed and outfeed ends, lateral upper rails 24 at the infeed andoutfeed ends of the upper longitudinal rail 21, legs 29 and additionallateral and longitudinal support rails 25, 26 extending between thelegs. A middle support axle 27 with two end rollers extends laterallyabove the upper longitudinal spine 21. Wheels 28 may extend below thelegs 29. The invention is not limited to the illustrative configuration,and a plurality of round, hollow tubes may be joined in any suitableconfiguration to provide support for a carryway.

The illustrative carryway 30, shown in FIGS. 6-8, is a unitary,homogenous structure formed of a low friction material, such as UHMW.The carryway comprises a plurality of longitudinal rails 31 forsupporting the conveyor belt connected by lateral rails 32, 33, 34. Wheninserted onto the support structure 20, the longitudinal rails 31 extendfrom the infeed 11 to the outfeed 12 in this particular embodiment. Thecarryway 30 further includes pins 36 extending from the bottom forengaging the middle support axle 27. As shown in FIG. 8, the pins 36extend from the bottom of two of the longitudinal rails 31 on each sideof the middle lateral rail 33. The unitary carryway 30 sits on top ofthe support structure 20, as shown in FIGS. 1, 2 and 5, and as describedin detail below.

The conveyor frame 10 further includes at least one belt and carrywaylifter, shown as infeed lifter 50 and outfeed lifter 60, for locking theposition of the carryway during operation and selectively lifting thecarryway and conveyor belt to allow cleaning or other access. FIGS. 1and 2 show the lifters 50, 60 in a down, operating position in which thecarryway 30 lies flat above the support structure 20. FIGS. 4 and 5 showthe lifters 50, 60 in a lift position, in which the carryway 30 israised at an angle above the support structure 20 and the conveyor belt40 is lifted above the carryway 30 for cleaning and access.

FIGS. 9-11 show the illustrative outfeed lifter 60. The outfeed beltlifter 60 comprises a lateral rail 61 that spans the width of thecarryway. The lateral rail 61 is received in openings 121, 122 in theoutfeed mounting plates (See FIGS. 3 and 25). One opening 121 may be aclosed hole and the other 122 an open slot with a narrow mouth. Thelateral rail 61 may have a notch or other narrowing to facilitateinsertion into the open slot 122. A handle 62 extends from a first endof the lateral rail in a forward direction. The illustrative handle 62is perpendicular to the lateral rail 61, though the invention is not solimited, and is horizontal in an operating position. The outfeed lifter60 includes latching arms 63 extending up from the lateral rail, 90°offset from the handle. The latching arms 63 form open seats for alateral rail 32 of the carryway, facing the same direction as the handle62 extends. Hooked arms 64 for raising the conveyor belt 40 extendforward down at an obtuse angle from the lateral rail, with the hooksfacing downwards. L-shaped arms 65 are disposed between the hooked arms64 and include a stem portion extending slightly forward and down fromthe lateral rail at a smaller angle than the hooked arms 64 and aperpendicular support portion that is parallel to the lateral rail 61for contacting the bottoms of two carryway longitudinal rails 31 to liftthe carryway. Vertical pins 66 are located outside the latching arms 63and extend up and down from the lateral rail 61 for locking side guards170, 171 securely in position when the carryway 30 is in operatingposition. A stop 68, comprising an L-shaped arm extends up and slightlyrearward from the latera rail 61 between the handle 62 and pin 66 tolimit rotation of the lifter.

In the illustrative embodiment, the placement of the elements of thelifter about the periphery of the lateral rail facilitates locking ofthe carryway during operating and lifting of the carryway and conveyorbelt during cleaning.

FIGS. 12-14 show the illustrative infeed lifter 50, which is similar tothe outfeed lifter, without the hooked arms 64. The components of theinfeed lifter 50 are basically mirror images to the components of theoutfeed lifter 60, without the hooked arms 64. The infeed belt lifter 50comprises a lateral rail 51 that spans the width of the carryway. Thelateral rail 51 is received in openings 111, 112 in the infeed mountingplates. One opening 111 may be a closed hole and the other 112 an openslot with a narrow mouth. The lateral rail 51 may have a notch or othernarrowing to facilitate insertion into the open slot 112A. handle 52extends from a first end of the lateral rail 51. The infeed lifter 50includes latching arms 53 extending up from the lateral rail 51 formingopen seats for a lateral rail 34 of the carryway. L-shaped arms 55 aredisposed between the latching arms 54 and include a stem portionextending from the lateral rail 51 and a perpendicular support portionthat is parallel to the lateral rail 51 for contacting the bottoms oftwo carryway longitudinal rails 31 to lift the carryway. The L-shapedarms 55 have a shorter stem portion than the L-shaped arms 65, so thatthe infeed lifter 50 lifts the carryway less than the outfeed lifter 60.Vertical pins 56 are located outside the latching arms 53 and extend upand down from the lateral rail 51 for locking side guards 170, 171securely in position when the carryway 30 is in operating position. Astop 58, comprising an L-shaped arm extends up and slightly opposite thelatching arms between the handle 52 and pin 56 to limit rotation of thelifter.

FIGS. 15 is a detailed, close-up view showing the outfeed lifter 60 in alowered, operating position. The outfeed lifter 60 is rotatably mountedto the outfeed plates 120. In this position, latching arms 63 engage thelateral rail 32 of the carryway to prevent longitudinal movement of thecarryway. Pins 66 prevent lateral movement of the carryway 30 when thecarryway is lifted in its cleaning position. Hooked arms 64 are loweredbelow the carryway and away from the belt, and L-shaped arms 65 are alsolowered and out of contact with the carryway rails 31.

FIG. 16A is a detailed, close up view showing the infeed lifter 50 in araised, cleaning position. The handle 52 is rotated up until arm 58abuts a stop 241 on the lateral arm 24 of the side plate 112. Rotationof the handle about rail 51 causes the latching arms 53 to disengage thecarryway lateral rail 34 and the L-shaped arms 55 to move up, pushingthe carryway rails 31 up.

FIG. 16B is a detailed, close up view showing the outfeed lifter 60 in araised, cleaning position. When handle 62 is rotated up until arm 68abuts stop 242 on the side plate 121. Rotation of the handle about rail61 causes the latching arms to disengage the carryway lateral rail 32and the L-shaped arms 65 to move up, pushing the carryway rails 31 up.Hooked arms 64 rise above the carryway rails to push the conveyor beltabove the carryway. Since L-shaped arms 65 are higher than L-shaped arms55, the outfeed of the carryway 31 is raised higher than the infeed.

FIG. 17 is a cross-sectional side view of the top portion of theconveyor frame in an operating position, with the lifters 50 and 60lowered. FIG. 18 is a detailed view of the infeed portion of FIG. 17.FIG. 19 is a detailed view of the middle portion of FIG. 17 and FIG. 20is a detailed view of the outfeed portion of FIG. 17. In the operatingposition, the handles 52, 62 are horizontal and extend toward thelongitudinal middle of the conveyor. Latching arms 53, 63 engage lateralrails 34, 32 on the carryway 30 and pins 36 engage the middle axle 27 ofthe frame with clearance and prevent longitudinal movement of thecarryway 30 when it is raised to ensure the latching arms 53, 63 areable to re-engage the lateral rails 34, 32 when it is lowered. Thecarryway 30 rests on lifter lateral arms 51, 61 during operation.

FIG. 21 is a cross-sectional side view of the conveyor frame in acleaning position, with the lifters 50 and 60 raised. FIG. 22 is adetailed view of the infeed portion of FIG. 21. FIG. 23 is a detailedview of the middle portion of FIG. 21 and FIG. 24 is a detailed view ofthe outfeed portion of FIG. 21. To lift the carryway and belt, thehandles 52, 62 are rotated to a raised position, shown in FIG. 21. Therotation of the hands 52, 62 rotates the connected lateral rails 51, 62,causing the latching arms 53, 63 to disengage the lateral carryway rails34, 32 and pushing the L-shaped arms 55, 65 to a raised position. TheL-shaped arms raise the carryway rails 31. The L-shaped arms 65 risehigher, so the raised carryway is higher at the outfeed end. The hookedarms 64 also rise, pushing up the conveyor belt, if present. The pins 36continue to engage the middle axle 27 to maintain the longitudinalposition of the carryway.

The illustrative hygienic conveyor also includes drive and infeed beltguides that are easy to clean. Referring to FIGS. 25-27, the outfeed 12comprises opposing mounting plates 120 at the outfeed end of thecarryway. The infeed 11 comprises opposing infeed plates 110 at theinfeed end of the carryway for mounting a roller-mounting assembly 116comprising opposing roller-mounting plates 117 connected by a rail 118and a shaped infeed roller 114 mounted to the roller-mounting plates 117for guiding the conveyor belt from the returnway to the carryway.

Each illustrative outfeed mounting plate 120 comprises a front opening,shown as a slot 123 with an integral inner bearing, for mounting a driveaxle of a conveyor belt drive, shown as a motorized sprocket 124. Abovethe slot, the mounting plate 120 includes a protrusion 126 forming apivot mount for a position limiter—scraper assembly 140. The mountingplate 120 further includes a rear opening 121, 122 for mounting theoutfeed belt lifter 60. In the illustrative embodiment, opening 121 is aclosed hole, while opening 122 is a slot open to the rear edge of thecorresponding mounting plate to facilitate mounting of the belt lifter60. A latch 142 extends from the bottom of the mounting plate 120 forlatching a leaf spring or other retainer on the position limiter—scraperassembly 140, as described below.

The illustrative hygienic conveyor shown in FIGS. 25-27 further includesside guards 170, 171 mounted to the frame for containing the conveyorbelt 40 on the carryway.

In one embodiment, one or both of the lifters 50, 60 can be used to lockthe side guards 170, 171 in place.

The position limiter—scraper assembly 140, an embodiment of which isshown in FIGS. 28 and 29 comprises a roller limiter 141 comprising aroller extending from a first end to a second end and axles 143extending from each end of the roller. During operation of the conveyorbelt, the roller limiter is designed to ensure proper engagement betweenthe drive elements on the conveyor belt and the drive structure on thedrive 124.

Opposing limiter connecting plates 150 connect the roller limiter 141 tothe conveyor frame. Each limiter connecting plate 150 comprises an upperhook 151 for mounting the plate to an outfeed mounting plate 120 viaprotrusion 126. A curved neck portion 152 forms a nook for theprotruding axle of the drive 124. Below the upper hook 151, an elongatedopening 153 receives a cylindrical cap 160 housing a bearing 161 forrotatably mounting the roller limiter axle 143. Adjacent the elongatedopening 153 an outward facing opening 155 includes top and bottomprotrusions 158, 156 forming a narrowed mouth to the opening 155enabling pivot of the scraper axle 171 about the fixed point of theroller limiter axle 143.

The limiter connecting plates 150 also mount a scraper assembly thatcontact the outer surface of the conveyor belt during operation toremove dirt and debris. A scraper mounting bar 171 extends between thetwo limiter connecting plates. The scraper mounting bar 171 extendsthrough the narrowed mouth of the opening 155. During operation, thescraper mounting bar 171 can move between the upper protrusion 158 andthe lower protrusion 156 of the limiter connecting plates 150 as itpivots under tension about the axis of the cylindrical cap 160. When thescraper blade 174 wears sufficiently, the scraper mounting bar 171 willfinally come into contact with the upper protrusion 158 and will ceaseto apply pressure to the belt, thereby requiring replacement of thescraper blade 174. If a large obstruction passes between the belt 40 andscraper blade 174, the scraper bar 171 will pivot downward and can comeinto contact with the lower protrusion 156, which limits the amount ofmovement the scraper blade 174 can move away from the belt 40. Arms 172connect each end of the scraper mounting bar 171 to the cylindrical cap160. A scraper blade 174 is mounted in scraper mounting taps 176 thatextend from the scraper mounting bar 171.

A tensioning and locking mechanism, shown as leaf spring 145, extendsrearward from the cylindrical cap 160 for locking the position limiterassembly 140 in an operating position and applying pressure to bias thescraper into a scraping position against the conveyor belt. The leafspring 145 comprises an enlarged central portion 146 with an opening 147for engaging the latch 142 of the outfeed mounting plate 130. Theillustrative leaf spring 145 utilizes 316 type stainless steel, which iscold rolled to harden it and make it suitable for use as a spring,though the invention is not limited. Any suitable means for tensioningthe scraper may be used.

In an operating mode, shown in FIGS. 26 and 27, the leaf spring 145 orother retainer is locked, and the limiter connecting plate 150 ispositioned relative to the mounting plate 130 to place outfeedcomponents in operating position. The roller limiter 141 is disposedrelative to the conveyor belt 40 to ensure proper engagement of the beltwith the drive 124. The cylindrical cap 160 is seated in the bottom ofthe opening 153. The scraper blade 174 is biased into contact with theouter surface of the conveyor belt to remove debris. The scrapermounting bar 171 operates between the lower protrusion 156 and upperprotrusion 158 of the mouth of the position limiter connecting plate150. The infeed roller 114 is positioned by the roller-mounting assemblyto guide the conveyor belt from the returnway to the carryway.

To move the position limiter assembly 140 to a cleaning position, theleaf spring 145 is unlatched from the latch 142, as shown in FIG. 30,and the position limiter assembly 140 is rotated up and out of positionabout the pivot point 126, as shown in FIG. 31. The position limiterassembly 140 can continue to rotate up to a cleaning position shown inFIG. 32, until the drive portion of the conveyor belt is exposed,allowing access for cleaning, repair or another purpose. In the cleaningposition, the cylindrical cap 160 falls into the opposite end of theopening 153 to allow access and cleaning of the opening 153. The scrapermounting bar 171 falls onto the upper protrusion 158 to allow access forcleaning.

The position limiter assembly 140 can then be easily rotated back intothe operating position and latched into place.

Alternatively, due to the open upper hook 151, the position limiterassembly 140 can be removed entirely from the conveyor frame by liftingthe assembly up and out of engagement with the pivot point 126 afterrelease of the latch, as shown in FIG. 33.

Referring to FIGS. 34-39, the infeed guide roller 114 and rollermounting assembly 116 can also be rotated out of place to facilitatecleaning. The roller mounting plates 117 include an open seat 119 facingoutwards for mounting axles on the infeed guide roller 114. An open seat113 mounts each roller mounting plate 117 to a corresponding infeedplate 110 and allows pivoting of the assembly 116 about the mountingplates 110 attached to the infeed end of the carryway.

The illustrative guide roller 114, as described below, comprises acontoured shaped roller having a series of convex and concave curvesforming peaks 1141 and troughs 1142. The guide roller comprises a fullyencapsulated central shaft 1143, which may be stainless steel to providestrength, and molded plastic encapsulating the central shaft and formingthe contoured body. End discs 1145 may also be formed as part of theunified body of the roller 114 and disposed on each end of the guideroller 114 for containing the conveyor belt. As shown in FIG. 39, theshaft 1143 may be entirely encapsulated in the plastic 1146, which maybe UHMW, forming the body of the roller and the end discs 1145. Thesculpted design of the roller 114 minimizes roller contact with theconveyor belt and reduces the spread of product while enabling the beltto be cleaned dynamically.

As shown in FIG. 40, the returnway rollers 70 may also comprise a shapedroller body with rounded wider portions 174 and narrower portions 175.The illustrative rollers also comprise a central shaft, such asstainless steel, encapsulated in plastic, such as UHMW. The returnwayrollers 70 are seated in returnway roller mounts 72, which compriserails extending up from lower spine 22 and terminating in open seatsthat receive the encapsulated ends of the returnway rollers.

As previously described, the illustrative hygienic conveyor frame 10comprises a number of hollow round rails, which provides strength whilereducing cost. The round rail promotes cleanliness, as there are noflats for water or product pooling. In one embodiment, a vacuum is drawnon the hollow interior of the rails and the vacuum is sealed. The vacuuminhibits the growth of all pathogens and other life within the hollowinterior of the frame and kills most living organisms within theinterior. As shown in FIG. 41, a sensor 210 monitors the hollow interiorand initiates an alert or prescribed corrective action if the hollow iscompromised. The sensor 210 is coupled to a port 202 in the conveyorframe and in communication with the hollow interior of the frame supportstructure 20.

The sensor can have any suitable size, shape, location, configuration ormeans of operating. Referring to FIGS. 42-45, one embodiment of a sensor210 comprises a printed circuit board 212 wired to measure pressure. Theprinted circuit board 212 can include an indicator, such as alight-emitting diode, that lights up when the seal has been breached, oranother condition is sensed. Other suitable indicators may be used. Theprinted circuit board 212 is housed in a housing 214. The electronicscan be removable for repair or replacement. The housing 214 comprises alower portion 215 having a threaded neck 216 for connecting to acorresponding port having interior threads in the conveyor frame, aninterior opening for the sensor 212 and an open path 219 to a mouth 217for placing the sensor 212 in communication with the conveyor framehollow when the neck is inserted in the port of the frame. Any suitablemeans for creating a sealed connection between the port and sensor maybe used, and the invention is not limited to a threaded connection. Theillustrative lower portion 215 is formed of stainless steel. The sensorhousing 214 also comprises a top portion 218 that coupled to the lowerportion 215 to seal the sensor. In the illustrative embodiment, the topportion and lower portion 215 mate through a threaded connection, thoughthe invention is not so limited. In the illustrative embodiment, the topportion 218 is formed of plastic. A seal, such as an 0-ring 220 sealsthe interface between the upper and lower housing portions. Anotherseal, shown as 0-ring 222 encircles the threaded neck 216 to seal theinterface between the frame port and the sensor 210.

FIGS. 46-49 show the process of inserting the sensor 210, drawing avacuum in a conveyor frame hollow and initiating monitoring of theconveyor frame hollow to ensure it remains sealed. A vacuum tool 350 isused to both insert the sensor 210 and draw sufficient vacuum in theconnected conveyor frame hollow to effect a kill zone throughout theconveyor frame interior.

In cases where the pathogens of concern are not adequately killed by thevacuum a concentrated amount of ozone can be inserted into the evacuatedhollow conveyor frame until the pathogens of concern have been killed.At such point the hollow conveyor frame can be re-evacuated to anappropriate level for the pressure monitor sensor to detect a futurebreach.

The vacuum tool 350 comprises a housing having a vacuum port 354connected to an air hose that creates a vacuum. The housing has an openchamber 356 at one end that can fit over the sensor 210. A seal, such as0-ring 358 seals the opening of the chamber 356. The vacuum tool 350further includes a wrench 360 that can move into the open chamber 356and rotate within the open chamber 356 to screw the sensor 210 into theconveyor frame port 202.

In a first step, shown in FIG. 46, the sensor 210 is partially screwedinto the port 202 of the conveyor frame 10, without sealing the conveyorframe. The sensor mouth and open path are placed in communication withthe hollow interior 206 of the conveyor frame. In a second step, shownin FIG. 47, the vacuum tool 350 is mounted over the sensor 210, creatinga seal. Then, air is evacuated from the frame interior 206, sensor 210and vacuum tool 350 via vacuum port 354, creating a vacuum that inhibitsthe growth of pathogens and all living matter within the frame interior206, and kills most living organisms within the interior. Next, as shownin FIG. 48, the wrench 360, or other suitable tool, engages the sensorhousing 214 to seal the port 202 with the sensor 210 while maintainingthe vacuum. The illustrative wrench 360 rotates within the chamber 356to screw in the sensor, but any suitable means for sealing the port withthe sensor may be used. Then, as shown in FIG. 49, the vacuum can bereleased and the vacuum tool 350 removed. The sensor 210 seals the port202 to maintain the vacuum within the hollow interior 206 of the frameand also monitors the condition of the hollow interior to detect anybreach in the vacuum.

In one embodiment, an indicator on the sensor can be used to signify theconditions in the conveyor frame interior. For example, the indicatorcan emit a yellow light during initiation of a kill cycle with thevacuum. The sensor can show a green light when the kill is complete, andthe evacuated interior is sealed. A red light can indicate that theinterior has been compromised.

The sensor 210 can utilize any suitable means for detecting andinitiating an alert if the vacuum is compromised. For example, thesensor can be an active short-range sensor, emitting a signal that canbe read on a nearby device, such as a blue tooth device. The sensor canbe an active long-range sensor, emitting a signal that can be read in acontrol room of a plant where one or more conveyors are monitored. Thesensor can be passive, using radio frequency identification (RFID) orother means that can be read by an active reader.

FIGS. 50-55 show another embodiment of a sensor 310 that can be used toseal and monitor a hollow interior of a conveyor frame. The sensor 310comprises a housing 314 having a neck 316 having an open mouth 317 andan interior for receiving electronics 312 for sensing a condition, suchas pressure. An electronics base plate 322 is also housed in the housing314. The illustrative housing 314 is plastic, but the invention is notso limited. The housing 314 forms a flange 323 having openings 324 forreceiving fasteners to mount the sensor 310 to a conveyor frame port incommunication with a hollow frame interior. A lower 0-ring 325 or othersuitable seal seals the interface between the port and the housing 314.A lid 315 is coupled to the housing 314 to seal the electronics withinthe interior of the housing 314. The lid 315 may be plastic, or anothermaterial, and be welded or otherwise sealed to the housing 314. The lidincludes an umbrella check valve 326 for applying a vacuum. A removableplug 318 is coupled to the lid to seal the sensor 310. The plug 318 canbe removed to apply a vacuum to evacuate the sensor and a connectedhollow frame interior.

FIGS. 56-60 show another embodiment of a sensor 410 that can be used toseal and monitor a hollow interior of a conveyor frame. The sensor 410comprises a lower housing 414 having a threaded neck 416 in whichelectronics 412 for measuring pressure are mounted. A lid 415 is coupledto the lower housing 414 and includes a check valve 422 to allowapplication of a vacuum. An 0-ring 425 seals the interface between thesensor and the associated port connecting to a hollow interior of aframe, and an outer cap 417 encapsulates the upper components of thesensor 410. The sensor 410 can be screwed into a threaded port of aconveyor frame designed to receive the sensor 410.

Another embodiment of a sensor that can be used to monitor a hollowinterior of a conveyor frame is shown in FIGS. 61-63. The sensor 510comprises an RFID tag 512 embedded in an opening 513 in a conveyor framerail 514 to an evacuated, hollow interior 506. The RFID tag 512 is opento the evacuated, hollow interior, with an antenna facing opposite. Apotting 516 covers the RFID tag 512 to seal the sensor from theenvironment. The RFID tag can be read to determine the pressure withinthe interior of the conveyor and ensure that the vacuum seal has notbeen breached.

The sensor for monitoring the pressure within a vacuum sealed conveyorframe interior can comprise any suitable configuration, communicationmeans, sensing means, mounting means and be inserted in any suitableport in the conveyor frame, not limited to the illustrative embodiments.

Although the invention has been described with reference to specificversions, other versions are possible. The scope of the invention is notmeant to be limited to the exemplary versions described in detailed.

1. A conveyor frame, comprising: a plurality of hollow sectionsconnected together to form a support structure for a carryway, thesupport structure extending longitudinally from an infeed end to anoutfeed end; and a sensor connected to one of said hollow sections forsensing a condition within the interior of the hollow sections.
 2. Theconveyor frame of claim 1, wherein the interior of the hollow sectionsis under a vacuum.
 3. The conveyor frame of claim 2, wherein the sensorsenses a breach in the vacuum.
 4. The conveyor frame of claim 1, furthercomprising a carryway on top of the support structure, the carrywaycomprising a plurality of longitudinal sections extending from theinfeed end to the outfeed end.
 5. The conveyor frame of claim 4, whereinthe longitudinal sections are connected by a plurality of lateralsections.
 6. The conveyor frame of claim 4, further comprising a set ofinfeed mounting plates at the infeed end and a set of outfeed mountingplates at the outfeed end.
 7. The conveyor frame of claim 6, furthercomprising a carryway lifter mounted to the infeed mounting plates forselectively raising the carryway above the support structure in acleaning mode.
 8. The conveyor frame of claim 6, further comprising acarryway and belt lifter mounted to the outfeed mounting plates forselectively raising the carryway above the support structure and raisinga conveyor belt above the carryway in a cleaning mode.
 9. The conveyorframe of claim 6, further comprising a drive mounted between the outfeedmounting plates and a position limiter—scraper assembly comprising aroller extending between two connecting plates mounted to the outfeedmounting plates and a scraper assembly having a scraper blade mounted tothe two connecting plates.
 10. The conveyor frame of claim 9, whereineach connecting plate includes an upper hook for pivotably mounting theposition limiter-scraper assembly to a corresponding protrusion on theoutfeed mounting plates.
 11. The conveyor frame of claim 10, furthercomprising a latch for latching the position limiter—scraper assembly tothe outfeed mounting plates.
 12. The conveyor frame of claim 11, whereinthe latch comprises a leaf spring extending from a cylindrical caphousing an end of the roller.
 13. The conveyor frame of claim 6, furthercomprising an infeed roller mounted to the infeed mounting plates, theinfeed comprising a contoured roller portion encapsulating a shaftextending from a first end to a second end.
 14. The conveyor frame ofclaim 1, wherein the support structure further comprises returnwayroller mounts and the conveyor frame further comprises returnway rollersmounted in the returnway roller mounts.
 15. The conveyor frame of claim14, wherein the returnway rollers comprise a shaft extending from firstend to a second end and an injection molded plastic portionencapsulating the shaft and forming enlarged portions for guiding aconveyor belt.
 16. A method of monitoring a hollow conveyor frame,comprising: drawing a vacuum in the interior of the hollow conveyorframe; and sensing a change in pressure in the interior using a sensorin communication with the interior.
 17. The method of claim 16, furthercomprising the step of: actuating an indicator if a change in pressurein the interior occurs.
 18. The method of claim 16, wherein the drawnvacuum is sufficient to inhibit the growth of bacteria.
 19. The methodof claim 16, further comprising the step of inserting a highconcentration of ozone into the hollow conveyor frame after drawing thevacuum.
 20. A hollow conveyor frame structure that supports a conveyorbelt circuit comprising: at least one hollow frame member, wherein theinterior of the hollow frame member is evacuated and sealed to have apressure that is lower than the pressure of the ambient environment sothat the pressure differential is negative; and a sensor incommunication with the sealed region for measuring the pressure of thesealed region.
 21. The hollow conveyor frame structure of claim 20,wherein the sensor communicates with a receiver.
 22. (canceled)
 23. Thehollow conveyor frame structure of claim 20, wherein the sensor receivesexcitation power wirelessly.
 24. (canceled)
 25. The hollow conveyorframe structure of claim 20, wherein the sensor measures pressure decayover a period of time. 26-42. (canceled)